1. Technical Field of the Invention
The present invention relates to a single color press which prints an identical image of the same color and shape onto a plurality of printing substrates placed on a frame, and a method of operating such a single color press.
A “Single color press” herein means a printing press for printing a single-layer image, which may be colored or colorless, on a printing substrate.
2. Description of Related Art
A flatbed press is one known method of forming the image of a flat panel display such as a liquid crystal display, plasma display, or EL (Electro Luminescence) display, on a flat glass substrate or a ceramic substrate.
As described in patent documents 1 and 2, a desired image is printed with a flatbed press by placing a flat plate on which a reverse image is formed, on a flat bed together with a flat printing substrate, and for example in the case of reverse printing, removing the ink that corresponds to the reverse image formed on the plate from the ink applied to the outer surface of a transfer cylinder, and transferring the image remaining on the transfer cylinder onto the printing substrate.
In Japanese Patent No. 3402974 (documents 1) and Japanese Patent No. 3434143 (documents 2) , single color presses are disclosed which reduce takt time by supporting two transfer cylinders in a rotatable manner on one moving carriage, and having each transfer cylinder in succession transfer an identical image of the same color and shape onto a printing substrate corresponding to that cylinder.
However, with the printing machines disclosed in patent documents 1 and 2, providing two transfer cylinders on a single moving carriage means that when transfer takes place from one of the transfer cylinders to one of the printing substrates, the other transfer cylinder also moves with the moving carriage, which forces unnecessary movement of the transfer cylinder that is not transferring to a printing substrate. This introduces dead time into the printing process and prevents takt time from being reduced.
The present invention takes into consideration the above circumstances, with an object of providing a single color press which shortens takt time by eliminating wastefulness from the printing process.
In order to solve the above problems, the single color press and operation method of the present invention employ the following measures.
That is, the single color press according to the present invention comprises: a first transfer cylinder which transfers an image to a first printing substrate; a first moving carriage which holds the first transfer cylinder in a rotatable manner and travels along a frame; a second transfer cylinder which transfers an image of the same color and shape as that of the image to a second printing substrate; and a second moving carriage which holds the second transfer cylinder in a rotatable manner and travels along the frame.
Since the first moving carriage and the second moving carriage are provided independently, printing can be performed by moving each transfer cylinder to transfer the image to the corresponding printing substrate, without being restricted by the movement of the other transfer cylinder. Thus, because each transfer cylinder is not forced to move together with the other transfer cylinder, wasted movement of the transfer cylinders can be all but eliminated. Accordingly, takt time can be shortened even more.
In addition, the single color press according to the present invention comprises a single plate which removes a reverse image from ink applied to the first transfer cylinder and the second transfer cylinder.
Because one such plate is provided, and this plate is used in common by the first transfer cylinder and the second transfer cylinder, printing onto two printing substrates can be executed using the one plate. Accordingly, equipment cost is lower than if two plates were provided.
Particularly in applications where the plate is mounted on top of a platen, because a common platen is used with each printing substrate, then only one alignment adjusting device for positioning the alignment of the platen with respect to the image printed on the platen and the printing substrate, and only one plate cleaning device is needed. Accordingly, the equipment cost can be further reduced.
Here, a “reverse image” means an image where the positive and negative regions are reversed with respect to the image to be printed on the printing substrates, and does not mean an image where the left and right or top and bottom directions have been reversed with respect to the image to be printed on the printing substrates.
In addition, in the single color press according to the present invention, when the first transfer cylinder is moved to a position of the first printing substrate after a reverse image is removed from the first transfer cylinder by the plate, the second transfer cylinder is moved from behind the first transfer cylinder to a position above the plate, and while the first transfer cylinder is transferring an image to the first printing substrate, a reverse image is removed from the second transfer cylinder by the plate.
By using a construction in which the second transfer cylinder moves from behind the first transfer cylinder to a position above the plate, removal of the reverse image by the plate can be performed successively without any wasted time.
Because the reverse image is removed from the second transfer cylinder by the plate, while the first transfer cylinder is transferring the image to the first printing substrate, the printing process can proceed without any waste of time, and takt time can be shortened.
Moreover, in the single color press according to the present invention, one coating device which applies ink to the first transfer cylinder and the second transfer cylinder is provided.
Because only one coating device is provided, the equipment cost can be reduced.
Furthermore, the single color press according to the present invention comprises; a first plate which removes a reverse image from the first transfer cylinder, and a second plate which removes a reverse image from the second transfer cylinder, and the first printing substrate and the second printing substrate are placed on a common printing platen during printing, and the first plate and the second plate are respectively provided on either side of the printing platen.
Because the first printing substrate and the second printing substrate are placed on a common printing platen, only one device for handling the printing substrates, and one alignment adjusting device for the printing platen are required.
Furthermore, because the first plate and the second plate are provided on either side of the printing platen, the first moving carriage and the second moving carriage can access the plates from both sides, and the carriages do not interfere with each other. Accordingly, takt time can be shortened.
Moreover, in the single color press according to the present invention, when transferring to the first printing substrate, alignment adjustment of the first plate is performed with respect to the printing platen, and when transferring to the second printing substrate, alignment adjustment of the second plate is performed with respect to the printing platen.
Because the alignment of the printing platen is different for each plate, adjustment is to the alignment of the plate corresponding to the printing substrate to which transfer is next performed. This enables precise printing.
In the case of a construction where the plate is placed on the platen, the plate alignment adjusting device adjusts the alignment of the plate by moving the platen.
In addition, in the single color press according to the present invention, the alignment of the second plate is adjusted so as to match the alignment of the printing platen with respect to the first plate.
Because the alignment of the printing platen with respect to the first plate is matched to the alignment of the printing platen with respect to the second plate, there is no need to change the alignment of the printing platen every time the printing substrate is set. Consequently, there is no need to distinguish between used platens every time printing is performed, which reduces the complexity of printer control and management.
Furthermore, a method of operating a single color press according to the present invention is a method of operating a single color press comprising: a first transfer cylinder which transfers an image to a first printing substrate; a first moving carriage which holds the first transfer cylinder in a rotatable manner and travels upon a frame; a second transfer cylinder which transfers an image of the same color and shape as that of the image to a second printing substrate; a second moving carriage which holds the second transfer cylinder in a rotatable manner and travels upon the frame; and a single plate which removes a reverse image from ink applied to the first transfer cylinder and the second transfer cylinder, wherein when the first transfer cylinder is moved to a position of the first printing substrate after a reverse image is removed from the first transfer cylinder by the plate, the second transfer cylinder is moved from behind the first transfer cylinder to a position above the plate, and while the first transfer cylinder is transferring an image to the first printing substrate, a reverse image is removed from the second transfer cylinder by the plate.
Because the transfer cylinder moves from behind the first transfer cylinder to a position above the plate, removal of the reverse image by the plate can be performed without any wasted time.
Because the reverse image is being removed from the second transfer cylinder while the first transfer cylinder is transferring the image to the first printing substrate, the printing process can proceed without any waste of time, and takt time can be shortened.
Furthermore, a method of operating a single color press according to the present invention is a method of operating a single color press comprising: a first transfer cylinder which transfers an image to a first printing substrate; a first moving carriage which holds the first transfer cylinder in a rotatable manner and travels upon a frame; a second transfer cylinder which transfers an image of the same color and shape as that the image to a second printing substrate; a second moving carriage which holds the second transfer cylinder in a rotatable manner and travels upon the frame; a first plate which removes a reverse image from the first transfer cylinder; and a second plate which removes a reverse image from the second transfer cylinder, in which the first printing substrate and the second printing substrate are each placed on the same printing platen during printing, wherein the first plate and the second plate are respectively provided on either side of the printing platen, the first moving carriage is moved from a position of the first plate towards the printing platen, and the second moving carriage is moved from a position of the second plate towards the printing platen.
Furthermore, in a method of manufacturing a liquid crystal color filter according to the present invention, a plurality of any of the above types of single color presses are provided, and images in at least R, G, and B ink are sequentially transferred to the first printing substrate and the second printing substrate.
In addition, a plurality of any of the above types of single color presses may be provided, and images in black matrix (light shielding film), R, G, and B ink may be sequentially transferred to the first printing substrate and the second printing substrate.
Furthermore, in the method of manufacturing a liquid crystal color filter according to the present invention, the method of operating any of the above types of single color presses is used to sequentially transfer images in at least R, G, and B ink to the first printing substrate and the second printing substrate.
In addition, the method of operating any of the above types of single color presses may be used to sequentially transfer images in black matrix (light shielding film), R, G, and B ink to the first printing substrate and the second printing substrate.
The present invention has the following effects.
By placing the first plate and the second plate on the same printing platen, only one device for handling the printing substrates and one device for aligning the printing platen are required.
Furthermore, by providing the first plate and the second plate on either side of the printing platen, the first moving carriage and the second moving carriage can access the plates from both sides, and the moving carriages do not interfere with each other. Accordingly, takt time can be shortened.